Two Union City men have pleaded guilty in what federal prosecutors and the recording industry call the biggest CD manufacturing piracy scheme ever uncovered in the United States.

Ye Teng Wen, 29, also known as Michael Wen, and Hao He, 30, also known as Kevin He, admitted Monday that from September 2004 through last Oct. 6, they used replication and silk-screening machines at Media Art Technology Inc. in Hayward and Union City to mass produce nearly 200,000 pirated music and software CDs, mostly Latino music titles and Norton anti-virus software.

Many of the pirated discs contained counterfeit FBI anti-piracy seals and silk-screened artwork to make them look legitimate.

Each of the men pleaded guilty to one count each of conspiracy to commit criminal copyright infringement and to traffic in counterfeit labels; criminal copyright infringement and aiding and abetting; trafficking in counterfeit labels and aiding and abetting; criminal trademark violations and aiding and abetting; and counterfeiting a department seal.

Each count is punishable by up to five years in federal prison and a fine of up to $250,000. Wen and He are scheduled to be sentenced Oct. 16 by U.S. District Court JudgeRonald Whyte of San Jose.

Another person indicted in the case — Yaobin Zhai, 33, of Fremont, also known as Ben Zhai — is scheduled to return to court May 22.

Agents who raided 13 California and Texas sites Oct. 6 as part of “Operation Remaster” seized nearly a half-million CDs and more than 5,500 stampers. A single stamper potentially can be used to manufacture 50,000 to 80,000 counterfeit CDs or DVDs of a single copyrighted work.

In pleading guilty, Wen and He agreed to forfeit their interest in equipment used in the scheme, including a replication machine, a silk-screening machine, a bar code printer and DVD 6 Bay replicators, as well as other items.

“The value of this prosecution to the entire music community cannot be overstated,” Brad Buckles, anti-piracy chief for the Recording Industry Association of America, said in a news release.

“This kind of illegal product has the greatest potential for deceiving the consumer and displacing legitimate sales,” he said. “The illegal profits generated by these highly sophisticated operations come at the expense of the artists, songwriters, retailers, record labels and many others whose creative energies make music possible.”